Difference between physical/logical/virtual memory address

Question

I am a little confused about the terms physical/logical/virtual addresses in an Operating System(I use Linux- open SUSE)

Here is what I understand:

Answer 1

Physical Address- When the processor is in system mode, the address used by the processor is physical address.

Not necessarily true. It depends on the particular CPU. On x86 CPUs, once you've enabled page translation, all code ceases to operate with physical addresses or addresses trivially convertible into physical addresses (except, SMM, AFAIK, but that's not important here).

Logical Address- When the processor is in user mode, the address used is the logical address. these are anyways mapped to some physical address by adding a base register with the offset value.

Logical addresses do not necessarily apply to the user mode exclusively. On x86 CPUs they exist in the kernel mode as well.

I have come across discussion that virtual and logical addresses/address space are the same. Is it true?

It depends on the particular CPU. x86 CPUs can be configured in such a way that segments aren't used explicitly. They are used implicitly and their bases are always 0 (except for thread-local-storage segments). What remains when you drop the segment selector from a logical address is a 32-bit (or 64-bit) offset whose value coincides with the 32-bit (or 64-bit) virtual address. In this simplified set-up you may consider the two to be the same or that logical addresses don't exist. It's not true, but for most practical purposes, good enough of an approximation.